update central custom hrm

Author: hathach

libraries/Bluefruit52Lib/examples/Central/central_custom_hrm/central_custom_hrm.ino

@@ -28,9 +28,9 @@
  * Body Sensor Location Char:   0x2A38 (Optional)
  */
 
-BLEClientService        clientHRM(UUID16_SVC_HEART_RATE);
-BLEClientCharacteristic clientMeasurement   (UUID16_CHR_HEART_RATE_MEASUREMENT);
-BLEClientCharacteristic clientSensorLocation(UUID16_CHR_BODY_SENSOR_LOCATION);
+BLEClientService        hrms(UUID16_SVC_HEART_RATE);
+BLEClientCharacteristic hrmc(UUID16_CHR_HEART_RATE_MEASUREMENT);
+BLEClientCharacteristic bslc(UUID16_CHR_BODY_SENSOR_LOCATION);
 
 void setup()
 {
@@ -46,21 +46,22 @@ void setup()
   Bluefruit.setName("Bluefruit52 Central");
 
   // Initialize HRM client
-  clientHRM.begin();
+  hrms.begin();
 
   // Initialize client characteristics of HRM.
-  // Note: Client Char will be added to the most recent Service that is initialized.
-  clientSensorLocation.begin();
+  // Note: Client Char will be added to the last service that is begin()ed.
+  bslc.begin();
 
-  clientMeasurement.begin();
-  clientMeasurement.setNotifyCallback(hrm_notify_callback); // set up callback for receiving measurement
+  // set up callback for receiving measurement
+  hrmc.setNotifyCallback(hrm_notify_callback);
+  hrmc.begin();
 
   // Increase Blink rate to different from PrPh advertising mode
   Bluefruit.setConnLedInterval(250);
 
   // Callbacks for Central
-  Bluefruit.Central.setConnectCallback(connect_callback);
   Bluefruit.Central.setDisconnectCallback(disconnect_callback);
+  Bluefruit.Central.setConnectCallback(connect_callback);
 
   /* Start Central Scanning
    * - Enable auto scan if disconnected
@@ -72,7 +73,7 @@ void setup()
   Bluefruit.Scanner.setRxCallback(scan_callback);
   Bluefruit.Scanner.restartOnDisconnect(true);
   Bluefruit.Scanner.setInterval(160, 80); // in unit of 0.625 ms
-  Bluefruit.Scanner.filterUuid(clientHRM.uuid);
+  Bluefruit.Scanner.filterUuid(hrms.uuid);
   Bluefruit.Scanner.useActiveScan(false);
   Bluefruit.Scanner.start(0);                   // // 0 = Don't stop scanning after n seconds
 }
@@ -102,7 +103,7 @@ void connect_callback(uint16_t conn_handle)
   Serial.print("Discovering HRM Service ... ");
 
   // If HRM is not found, disconnect and return
-  if ( !clientHRM.discover(conn_handle) )
+  if ( !hrms.discover(conn_handle) )
   {
     Serial.println("Found NONE");
 
@@ -112,18 +113,18 @@ void connect_callback(uint16_t conn_handle)
     return;
   }
 
-  // HRM is found
+  // Once HRM service is found, we continue to discover its characteristic
   Serial.println("Found it");
   Serial.println("Discovering Measurement and Body location characteristic ... ");
 
-  uint8_t num_found_chr = Bluefruit.Discovery.discoverCharacteristic(conn_handle, clientMeasurement, clientSensorLocation);
+  uint8_t num_found_chr = Bluefruit.Discovery.discoverCharacteristic(conn_handle, hrmc, bslc);
 
   Serial.print("Found ");
   Serial.print(num_found_chr);
   Serial.println("Characteristics");
 
   // Measurement chr is mandatory, if it is not found (valid), then disconnect
-  if ( !clientMeasurement.isValid() )
+  if ( !hrmc.isValid() )
   {
     Serial.println("Measurement characteristic not found");
     Bluefruit.Central.disconnect(conn_handle);
@@ -133,21 +134,21 @@ void connect_callback(uint16_t conn_handle)
 
   // https://www.bluetooth.com/specifications/gatt/viewer?attributeXmlFile=org.bluetooth.characteristic.body_sensor_location.xml
   // Body Sensor Location is optional, print its location (in text) if present
-  if ( clientSensorLocation.isValid() )
+  if ( bslc.isValid() )
   {
     // Body sensor location value is 8 bit
     const char* body_str[] = { "Other", "Chest", "Wrist", "Finger", "Hand", "Ear Lobe", "Foot" };
 
     uint8_t loc_value = 0;
-    if ( clientSensorLocation.read(&loc_value) )
+    if ( bslc.read(&loc_value) )
     {
       Serial.print("Body Location Sensor: ");
       Serial.println(body_str[loc_value]);
     }
   }
 
   // Reaching here means we are ready to go, let's enable notification on measurement chr
-  if ( clientMeasurement.enableNotify() )
+  if ( hrmc.enableNotify() )
   {
     Serial.println("Ready to receive HRM Measurement value");
   }else
@@ -173,7 +174,7 @@ void disconnect_callback(uint16_t conn_handle, uint8_t reason)
 /**
  * Hooked callback that triggered when a measurement value is sent from peripheral
  * @param chr   Reference to client characteristic that even occurred,
- *              in this example it should be clientMeasurement
+ *              in this example it should be hrmc
  * @param data  Pointer to received data
  * @param len   Length of received data
  */
@@ -185,7 +186,6 @@ void hrm_notify_callback(BLEClientCharacteristic& chr, uint8_t* data, uint16_t l
 
   Serial.print("HRM Measurement: ");
 
-
   if ( data[0] & bit(0) )
   {
     uint16_t value;